Port: Fix skill subcommand help handling (#708)

Upstream sha a264199177.

`install`, `link`, `update` and `check` render static help before entering
any operational path, through both the top-level verb and the legacy `skills`
namespace, for `--help` and `-h` alike.

Verified against origin/main's `cli/bin/cli.js`: all six spellings produce
identical text and exit codes.

Oracle: a new `tests/oracle/cases/skills.mjs` with seven help cases. Only the
help paths are pinned there; every other installer path writes into harness
directories or reaches the network.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vau2X53xGTjjTCXWMVBoNY

crates/skills/src/commands.rs

@@ -15,9 +15,40 @@ use crate::util::{self, pad_end, utf16_len, utf16_prefix};
 use crate::{Flow, R};
 
 /// JS: skills.mjs#run(args)
+/// JS: skills.mjs#SUBCOMMAND_HELP (#708). Static help for a sub-command, so
+/// `install --help` never enters an operational path.
+const SUBCOMMAND_HELP: &[(&str, &str)] = &[
+    (
+        "install",
+        "Usage: impeccable install [options]\n\nInstall compiled Impeccable skills into project or user-level harness folders.\n\nOptions:\n  -y, --yes              Accept detected defaults without prompting\n  --providers=<names>    Comma-separated harnesses to install\n  --scope=<scope>        Install scope: project or global\n  --project              Install into the current project\n  --user, --global       Install at the user level\n  --no-hooks             Install skills without provider hook manifests\n  --force                Replace an existing installation\n  -h, --help             Show this help message",
+    ),
+    (
+        "link",
+        "Usage: impeccable link [options]\n\nLink Impeccable skills from a local checkout or submodule.\n\nOptions:\n  --source=<path>        Source checkout (default: .impeccable)\n  --providers=<names>    Comma-separated harnesses to link\n  -y, --yes              Accept detected defaults without prompting\n  --force                Replace existing skill folders with links\n  -h, --help             Show this help message",
+    ),
+    (
+        "update",
+        "Usage: impeccable update [options]\n\nUpdate an existing Impeccable skill installation.\n\nOptions:\n  -y, --yes              Accept detected defaults without prompting\n  --scope=<scope>        Update scope: project or global\n  --project              Update the current project installation\n  --user, --global       Update the user-level installation\n  --no-hooks             Update skills without changing hook manifests\n  --force                Replace installed skill files\n  -h, --help             Show this help message",
+    ),
+    (
+        "check",
+        "Usage: impeccable check [options]\n\nCheck whether installed Impeccable skills are up to date.\n\nOptions:\n  -h, --help             Show this help message",
+    ),
+];
+
+fn subcommand_help(sub: &str) -> Option<&'static str> {
+    SUBCOMMAND_HELP.iter().find(|(k, _)| *k == sub).map(|(_, v)| *v)
+}
+
 pub fn run(args: &[String], io: &mut Io) -> R<()> {
     let sub = args.first().map(String::as_str).unwrap_or("");
     let rest: Vec<String> = args.iter().skip(1).cloned().collect();
+    if let Some(help) = subcommand_help(sub) {
+        if rest.iter().any(|a| a == "--help" || a == "-h") {
+            out(io, help);
+            return Ok(());
+        }
+    }
     match sub {
         "" | "help" | "--help" | "-h" => show_help(io),
         "install" => install(&rest, io),

tests/oracle/cases/skills.mjs

@@ -0,0 +1,17 @@
+/**
+ * The installer verbs' static help (`install`, `link`, `update`, `check`).
+ *
+ * Only the help paths are pinned here: every other installer path writes into
+ * harness directories or reaches the network, which the corpus keeps out. The
+ * help text must render before any operational path runs (#708), through both
+ * the top-level verb and the legacy `skills` namespace.
+ */
+export default [
+  { id: 'skills-install-help', verb: 'install', args: ['--help'] },
+  { id: 'skills-install-help-short', verb: 'install', args: ['-h'] },
+  { id: 'skills-link-help', verb: 'link', args: ['--help'] },
+  { id: 'skills-update-help', verb: 'update', args: ['--help'] },
+  { id: 'skills-check-help', verb: 'check', args: ['--help'] },
+  { id: 'skills-namespace-install-help', verb: 'skills', args: ['install', '--help'] },
+  { id: 'skills-namespace-check-help-short', verb: 'skills', args: ['check', '-h'] },
+];

tests/oracle/golden/skills-check-help.json

@@ -0,0 +1,7 @@
+{
+  "stdout": "Usage: impeccable check [options]\n\nCheck whether installed Impeccable skills are up to date.\n\nOptions:\n  -h, --help             Show this help message\n",
+  "stderr": "",
+  "exit": 0,
+  "signal": null,
+  "files": {}
+}

tests/oracle/golden/skills-install-help-short.json

@@ -0,0 +1,7 @@
+{
+  "stdout": "Usage: impeccable install [options]\n\nInstall compiled Impeccable skills into project or user-level harness folders.\n\nOptions:\n  -y, --yes              Accept detected defaults without prompting\n  --providers=<names>    Comma-separated harnesses to install\n  --scope=<scope>        Install scope: project or global\n  --project              Install into the current project\n  --user, --global       Install at the user level\n  --no-hooks             Install skills without provider hook manifests\n  --force                Replace an existing installation\n  -h, --help             Show this help message\n",
+  "stderr": "",
+  "exit": 0,
+  "signal": null,
+  "files": {}
+}

tests/oracle/golden/skills-install-help.json

@@ -0,0 +1,7 @@
+{
+  "stdout": "Usage: impeccable install [options]\n\nInstall compiled Impeccable skills into project or user-level harness folders.\n\nOptions:\n  -y, --yes              Accept detected defaults without prompting\n  --providers=<names>    Comma-separated harnesses to install\n  --scope=<scope>        Install scope: project or global\n  --project              Install into the current project\n  --user, --global       Install at the user level\n  --no-hooks             Install skills without provider hook manifests\n  --force                Replace an existing installation\n  -h, --help             Show this help message\n",
+  "stderr": "",
+  "exit": 0,
+  "signal": null,
+  "files": {}
+}

tests/oracle/golden/skills-link-help.json

@@ -0,0 +1,7 @@
+{
+  "stdout": "Usage: impeccable link [options]\n\nLink Impeccable skills from a local checkout or submodule.\n\nOptions:\n  --source=<path>        Source checkout (default: .impeccable)\n  --providers=<names>    Comma-separated harnesses to link\n  -y, --yes              Accept detected defaults without prompting\n  --force                Replace existing skill folders with links\n  -h, --help             Show this help message\n",
+  "stderr": "",
+  "exit": 0,
+  "signal": null,
+  "files": {}
+}

tests/oracle/golden/skills-namespace-check-help-short.json

@@ -0,0 +1,7 @@
+{
+  "stdout": "Usage: impeccable check [options]\n\nCheck whether installed Impeccable skills are up to date.\n\nOptions:\n  -h, --help             Show this help message\n",
+  "stderr": "",
+  "exit": 0,
+  "signal": null,
+  "files": {}
+}

tests/oracle/golden/skills-namespace-install-help.json

@@ -0,0 +1,7 @@
+{
+  "stdout": "Usage: impeccable install [options]\n\nInstall compiled Impeccable skills into project or user-level harness folders.\n\nOptions:\n  -y, --yes              Accept detected defaults without prompting\n  --providers=<names>    Comma-separated harnesses to install\n  --scope=<scope>        Install scope: project or global\n  --project              Install into the current project\n  --user, --global       Install at the user level\n  --no-hooks             Install skills without provider hook manifests\n  --force                Replace an existing installation\n  -h, --help             Show this help message\n",
+  "stderr": "",
+  "exit": 0,
+  "signal": null,
+  "files": {}
+}

tests/oracle/golden/skills-update-help.json

@@ -0,0 +1,7 @@
+{
+  "stdout": "Usage: impeccable update [options]\n\nUpdate an existing Impeccable skill installation.\n\nOptions:\n  -y, --yes              Accept detected defaults without prompting\n  --scope=<scope>        Update scope: project or global\n  --project              Update the current project installation\n  --user, --global       Update the user-level installation\n  --no-hooks             Update skills without changing hook manifests\n  --force                Replace installed skill files\n  -h, --help             Show this help message\n",
+  "stderr": "",
+  "exit": 0,
+  "signal": null,
+  "files": {}
+}